Kern River, CA

The Kern River is a river in the U.S. state of California, approximately 165 miles (266 km) long. It drains an area of the southern Sierra Nevada mountains northeast of Bakersfield. Fed by snowmelt near Mount Whitney, the river passes through scenic canyons in the mountains and is a popular destination for whitewater rafting and kayaking. It is the only major river in the Sierra Nevada mountain range that drains in a southerly direction.

The Kern River formerly emptied entirely into now dry Buena Vista Lake at the southern end of the Central Valley. The river has been almost entirely diverted for irrigation, recharging aquifers and the California Aqueduct, although some water empties into Lake Webb and Lake Evans, two small lakes in a portion of the former Buena Vista Lakebed. The lakes were created in 1973 for recreational use. The lakes hold 6,800 acre feet (8,400,000 m3) combined. Crops are grown in the rest of the former lakebed. In extremely wet years the river will reach the Tulare Lake basin through a series of sloughs and flood channels.

The Kern River is the southernmost river in the San Joaquin Valley. It begins in the Sierra Nevada on the eastern side of Tulare County and ends on the west side of Kern County where it is mainly diverted for local water supplies. The main branch of the river (sometimes called the North Fork Kern River) rises from several small lakes west of Mount Whitney in the high Sierra Nevada mountains in northeastern Tulare County, in the northeast corner of Sequoia National Park. It flows south through the mountains, passing through Inyo and Sequoia national forests, and the Golden Trout Wilderness. The Little Kern River joins from the northwest at a site called Forks of the Kern.

At Kernville the river emerges from its narrow canyon into a widening valley where it is impounded in Lake Isabella, a reservoir formed by Isabella Dam. The area was once known as Whiskey Flat, the former location of the town of Kernville. The South Fork Kern River joins in Lake Isabella. Like the North Fork, the South Fork rises in Tulare County and flows mainly south, through Inyo National Forest. After entering Kern County the South Fork curves to the west and flows into Lake Isabella.

Below Isabella Dam the Kern River flows southwest through a spectacular rugged canyon along the south edge of the Greenhorn Mountains, emerging from mountains east of Bakersfield, the largest city on the river. In the Kern's lower course downstream from Bakersfield the river is highly diverted through a series of canals to irrigate the farms of the southern San Joaquin Valley and provide municipal water supplies to the City of Bakersfield and surrounding areas. In this region near Bakersfield the Kern River once spread out into vast wetlands and seasonal lakes.

Due to water diversion and Isabella Dam the Kern River's discharge changes considerably over its length. The highest mean annual flows occur just downriver of Isabella Dam, but because the dam serves to regulate the flow of water the highest daily discharges occur above the dam on the North Fork section of the Kern River. The USGS stream gage on the North Fork Kern River has recorded an average annual mean discharge of 806 cubic feet per second (ft³/s) and a maximum daily discharge of 33,600 ft³/s, and the gage on the South Fork Kern River shows an average annual mean of 123 ft³/s and a maximum daily discharge of 14,000 ft³/s. In contrast the first stream gage below Isabella Dam has recorded an average annual mean of 946 ft³/s but a maximum daily discharge of only 7,030 ft³/s. Due to water withdrawals the three stream gage stations below Isabella Dam show a dramatically decreasing discharge. At the last gage, near Bakersfield, the river's average flow is only 312 ft³/s.

The deep canyon of the river northeast of Bakersfield is a popular location for fly fishing and particularly famous for whitewater sports including whitewater rafting, whitewater kayaking, and riverboarding.